Influences of synergy effect retarders with superplasticizers on the performances of sulfo-aluminate expansive agents

The influences of synergy effect of sodium tripolyhosphate,sodium gluconate and naphthalene series,amino sulfonic superplasticizers on the performances of sulfo-aluminate expansive agents were investigated respectively.The results showed that the synergy effect of retarders used together with superplasticizers can reduce the restrained-expansion rate and free-expansion rate of ulfo-aluminate expansive agents' mortar specimens in water or air curing condition,but the expansion indexes of mortar specimens at 28 d in water curing condition increase,so resulting in the reduction of efficient expansion energy of expansive agent.Therefore,under the same amount used,synergy effect of retarders and superplasticizers can obviously decrease the shrinkage-compensation action or self-stress of sulfo-aluminate expansive agent for concrete.